This invention generally relates to seal structures for Surface Effect Ships (SES) and more particularly to a seal structure which includes transverse reinforcing means for reducing weight requirements and the effects of impact loads. The invention can be used as a bow seal and, by rotating the total structure, also as a stern seal. However the advantages of this seal are more apparent when used as a bow seal. The description below applies to the invention when used in this way.
Hitherto this invention comprised an inflatable bag structure secured to the ship hull, between the vessel's sidewalls and a stiffened lobe portion transversely supported and secured beneath the bag. The lobe portion consisted of a membrane with an array of laterally arranged, longitudinally spaced transverse stiffening means secured thereto. Each transverse stiffening means was preferably segmented into a plurality of light weight elongated stiffener member which comprised glass reinforced plastic (GRP) planks.
The GRP Planks were continuous members, i.e. not segmented, and under the combined effects of air pressure and waves, these GRP planks developed high stress areas which produced cracks in the planks.